In color reproduction systems, color transformation methods have been employed to compensate for colorant characteristics, reproduction system dissimilarities, subject matter requirements, and personal preferences of the operators and directors. Color transformation may be used to perform digitizing of color images, editing color images, and inter-device color control. There are two common approaches to color transformation, which is the eventual task of a general process known as “system feedback programming for color separation,”: integrative approach and component approach (Gary G. Field, Color & Its Reproduction, 2nd rev. edition, Gatf Press, Mar. 1, 1998). Currently, the prevailing approach in performing color transformation for inter-device color control is the integrative method. The integrative method uses lookup tables that define a device's characteristics by associating pairs of hypercube colorant coordinates and colorimetric measurement or mathematical calculation values of the resultant or predicted actual color appearance. The lookup table incorporates data integratively representative of the system's variables in tone-reproduction, gray-balance, and hue/saturation characteristics correction. However, a major disadvantage of the integrative approach is that once a reproduction system is characterized, the lookup tables are fixed and not readily modifiable to accommodate new non-integrated data representative of a wide variety of dynamic printing condition changes. In typical commercial printing environments, printing condition changes may include day-to-day or hour-to-hour paper stock variations that exhibit variable light scattering effect characteristics, paper color differences, proofs manufactured out of perfect tone-reproduction specifications, ambient climate changes around the printing device, and personal preferences of the on-press director, among others. These condition changes may alter some component characteristics but not others, and alter the component characteristics to varying degrees or differently.
The component approach, unlike the integrative approach, gives color specialists the ability to separately correct for the uniqueness of a color reproduction system's isolated one-reproduction, gray-balance, and hue/saturation characteristics or attributes. Traditional practice has show that the component approach can be an accommodating and expansive course of action in achieving high quality color separations in performing the tasks of digitizing and editing color images and it is reasonable to believe that this approach could also significantly improve the industry's performance of inter-device color control.